I was just cleaning up my office (here is a picture of the disaster area in progress)
The good thing about cleaning up is that you find things that are otherwise buried. So somewhere under the pile on the desk, I came on a very interesting paper from March, entitled "The Rise in Firm-Level Volatility: Causes and Consequences,", by Diego Comin and Thomas Phillippon.
The bottom line is that sales of individual companies bounce around a lot more than they used to. They also have a great chart showing that the turnover of industry leaders is much greater.
I don't know how long GM has been the world leader in autos--75 years? But we may never see its like again.